To beat
feet means to go somewhere quickly. It can be used as either an explanation for having to rush some place (eg. I had to beat feet to get there on
time), or for telling someone to get away (eg. He wanted to hang out with us, but I told him to beat feet). Common term in the
Army.
The drill sergeant was yelling at me to hurry up, so I had to beat
feet in order to get there before he lost it!
This dude was trying to
hang out with me and my bros, but we told him to beat
feet because he’s a nerd.